Here's the situation on my 1973 JH. I have an intermittent problem. At random intervals I will suddenly loose my tachometer, fuel gauge, and voltmeter -- they all just drop to zero. They always seem to go out at the same time and they usually come back at the same time, usually a few minutes later. Although sometimes the gas gauge and the voltmeter will come back before the tach. So I figure I have some sort of electrical problem.

Now, here's the wrinkle. Today I was out driving on the freeway and the car died. It felt like it suddenly ran out of gas. I shut it off, waited about 30 seconds and then it started up again and I was on my way. But, it happened two more times before I got home. I checked the fuel filter and it's clean so I'm thinking maybe I have a fuel pump that's going out. But, before I change the fuel pump -- it there a single electrical problem that could be causing both things? It could be the fuel pump or it could be the power to the fuel pump (The gauges were malfunctioning at the time).

Before I change out the fuel pump has anyone experienced this particular set of symptoms? Feel free to speculate, that's what I'm doing : )

Both the fuel pump and the gauges are on circuits that go thru the middle fuse. You may try cleaning those electrical connections. If you search here on the forum, there are several threads about cleaning up the connections at the fuse box. That would be my guess as the best place to start. I would also guess that you problem is electrical rather than a bad fuel pump. Hope this helps and good luck.

The fuse box and its 3 fuses can be the source of much anguish. Once you get into it a way you'll see why. Prince of darkness and all that. It is fixable with patience and trust and some good wine or brew can help. Good Luck

When I posted above that both gauges and fuel pump go thru the middle fuse I was using former member John Kimbrough's wiring diagrams. The JH owners handbook says the gauges are on the top fuse, does not mention the fuel pump. I would guess the top fuse controls both.

The fuel pump itself is not fused; the "inner" or "HOT" side of the fuse box(closest to the center of the car) has a link on the inside running from the top fuse down to the second/middle fuse. There, a white wire(inside the car) runs back to the pump.
However, Tim & Dwalls are correct in that eventually the fuses and their contacts need to be cleaned(a good hard fiberglass brush is useful here). This may solve your problems, but it should be the starting point. If you have a friend who is VOM knowledgeable, that should make the process faster; fortunately, the wiring from cars of this vintage is fairly easy and simple.
Years ago, I borrowed my friends Datsun 2000 for a date, and when I was almost home, everything went "dead". Apparently, we found one of the main battery posts was cracked causing failure.
Keep us posted.
bruce

Pacer Technologies is known for their line of ZAP super glues, but they also make Rail Zip II. Electric model train guys use it to keep the electrified brass rails free of corrosion that would cause continuity problems.

I use Rail Zip II to clean all the little Britcar bullet, spade and fuse connections that tend to lose continuity just sitting around. Simply pull the connection apart, put a drop on the mating ends, and push it back together again. Yes, if the connection is actually crusty with scale, it speeds things up to manually remove the worst of it. Barring that worst case condition, just pull the connection apart, add a little Rail Zip, and put it back together. No need to work it back and forth or scrape, just re-connect it, leave it alone, and let Rail Zip do it's thing.

There's no need to go back in and clean-up later since Rail Zip will do no long term harm to the metal bits or insulation. It just goes after the corrosion.

Rail Zip II is available through online model train hobby shops and Amazon. Or go to your local hobby shop that caters to the model train crowd and pick-up a small bottle. In my local hobby shop, it's in the glue section with the rest of Pacer Technologies' products. Ask!

I had the exact same issue with my car a while back. It was the voltage stabilizer. New one from Moss, problem solved. HOWEVER.....it was only the tach and gauges that quit, not the fuel pump. That may be a separate issue.